Vehicles are indispensable to everyday living or social activities, and use fossil fuels (e.g. petroleum) as their energy source. However, fossil fuels have limited deposits, which are being depleted as time passes by, and the prices are on the rise.
Particularly, fossil fuels discharge, when used, not only exhaust gases, which contaminate atmosphere environments, but also a large amount of carbon oxide, which is a major cause of global warming. Therefore, there have been global research and development activities to reduce carbon emission throughout the entire industries, and electric vehicles have been developed, which use electricity as their energy source, as a result of such efforts.
Electric vehicles include battery-powered electric vehicles, which are solely powered by electricity, hybrid electric vehicles, which use both motors and engines, and fuel cell electric vehicles. In addition, widespread use of electric vehicles requires construction of a charging infrastructure, which enables easy charging at any time and location, and relevant research is in progress.
However, unlike conventional vehicles using electric vehicles charge their batteries in a plug-in type, meaning that consumers need to wait for a long time, which inconveniences the consumers and degrades economic merits of charging facility operators.
In an attempt to solve the above-mentioned problem, it has recently been proposed that, instead of charging the battery of an electric vehicle, a battery be charged in advance, and the fully-charged battery replace a depleted one (hereinafter, referred to as a battery exchange type).
Such a battery exchange type is advantageous in that, when a consumer visits a charging station to charge the battery, he/she can exchange the depleted battery with a fully-charged one and mount it. This requires no charging time and thus conveniences the consumer.
However, batteries are expensive, and efficient resource utilization requires management of batteries exchanged in charging stations. For example, when vehicles concentrate on a specific charging station, there may not be sufficient batteries, making some consumers visit in vain. In the opposite case, batteries may be left unused for a long period of time.
Furthermore, when battery exchange-type electric vehicles are used as electric buses traveling along a predetermined line, they need charging stations capable of convenient and rapid battery exchange.